PB1768: IS NATIVE E-COLI OR PEG-ASPERAGINASE FORMULATION A HIGHER RISK FOR VTE DEVELOPMENT IN PATIENTS WITH POST TREATMENT ACUTE LYMPHOBLASTIC LEUKEMIA? A META-ANALYSIS
Authors: J. T. Seki, E. Atenafu, H. Sibai
Journal: HemaSphere (2022)

Background: Thrombosis, is one of the serious complications of asparaginase-containing chemotherapy in Adult Acute Lymphoblastic Leukemia (AALL), reeks considerable morbidity and mortality. A large meta-analysis of 17 studies reported that symptomatic VTE in children is low (about 5%), post asparaginase-chemotherapy (Caruso 2006). Prospective screening of asymptomatic children revealed that the VTE rate can reach as high as 32% post native Asparginase (NEA) treatment (Mitchell LG 2003). Given the paucity of data in AYA, ALL patients receiving PEG-a, Underwood B. 2020 et al, reported an amazingly high VTE rate of 41%, with the cumulative incidence rate of 25% after an initial dose within 30 days. As age advance from the teen years, to adolescent and young adult (AYA), to older than 30 years, the VTE rates picked up momentum rapidly from 20%, 25% to 42% respectively (Grace RF et al in 2011). However, in a similar age group, Stock et al 2019 revealed a mere 5% VTE in patients with PEG-a experience. Aims: Given the seemingly high symptomatic VTE incidence, especially in PEG-a recipients, we would like to get a better understanding of which asparaginase formulation instigating thrombosis more intensely while under the influence of pharmacological prophylaxis (LMWH) in the reduction of VTE rates. Methods: Review of studies and abstracts from PubMed, Medline, published between 2006 and 2021 with study designs (excluding case reports) on VTE incidences reported as primary or secondary objective. Thrombosis incidences from the published studies using either the NEA or the PEG formulation in the treatment of AALL are identified. The VTE incidence from each of the NEA and PEG involved studies are abstracted. The significance of these is compared. Intervention with the use of LMWH prophylaxis, although in limited number of studies, for the prevention of VTE rates are compared for effectiveness between NEA and PEG-a groups. Results: In this meta-analysis, the data showed that while LMWH as thrombo-prophylaxis is effective and beneficial in the NEA recipients [47/191 (24.61%) vs. 24/200 (12.00%), p=0.0012]. However, in spite of that, LMWH prophylaxis did not have significant impact on the development of VTE rates in the PEG-a treated patients (22/120 (18.33%) vs. 7/23 (30.43%), p=0.1861). This may be due to the fact that the number of patients receiving LMWH prophylaxis is low in adult patients receiving PEG-a containing protocol. A larger sample size and more prophylaxis containing PEG-a studies are needed to show a potential difference in the impact of LMWH in these patients. Image:Summary/Conclusion: In this meta-analysis, the data showed that while LMWH as thrombo-prophylaxis is effective and beneficial in the NEA recipients (24.61% vs. 12.00%, p=0.0012). However, in spite of that, LMWH prophylaxis did not have significant impact on the development of VTE rates in the PEG-a treated patients (22/120 (18.33%) vs. 7/23 (30.43%), p=0.1861). This may be due to the fact that the number of patients receiving LMWH prophylaxis is low in adult patients receiving PEG-a containing protocol. A larger sample size and more prophylaxis containing PEG-a studies are needed to show a potential difference in the impact of LMWH in these patients.